Why Do We Have Allergies? 

"A-choo, a-choo, so itchy..." Mackle did not expect he was allergic to pollen! Now, Mackle was standing in the middle of flowers. He felt uncomfortable like staying in the "death hell". In his memory, this feeling was not common and may happen for only one time when he was a baby. At that time, Mom took him to a garden and he began to cry. She thought that he just lost his temper. So she took him back home and didn't go to the hospital to do examination. However, this symptom seemed worse this time. He felt that he was choked, sneezing with a runny nose. And he also felt hot and itchy. Mom realized that he was really not "likeable for flowers". She was aware of that Mackle was probably allergic to things like pollen. Therefore, she decided to take him to the hospital for a thorough physical examination for finding out allergens.

As they arrived at hospital, the doctor conducted a very professional allergen testing and explained, "Allergy is the reaction of the immune system for foreign substances. Substances causing allergies are generally harmless to most people. The substance that causes allergies is called 'allergen'. The symptoms are similar when people have allergies. However, it does not mean that their allergens are the same. Here are some common allergens: dust mites, animal dander or feathers, insect venom, pollen, mildew, foods and certain medicines. Your little boy is allergic to pollen. So don't let him be exposed to any possible allergen again, ok? You should be more thoughtful for prevention in the pollen season."

Mackle wanted to know why people have allergies. The doctor said, "It's very complicated for children to understand, do you want to know?" Mom said, "It's not a big deal for my little boy." The doctor said with a smile, "Is that true? Then I will explain to you. It never hurts to learn. When you are exposed to allergens, nearby immune cells will come to resist them. Immune cells will break them down into smaller pieces, 'stick' these pieces on themselves, and then go to lymphoid tissue with these pieces. Those pieces will be given away to other immune cells there. Then these cells will work together to produce a special antibody, immunoglobulin E (IgE). The whole process is called 'sensitization'.

If you are not exposed to allergens, that's not a big deal. However, these antibodies become powerful weapons against allergens when you are exposed to the allergens again. And these antibodies will be your 'trouble' for the reasons that immunoglobulin E will lead to the emergence of some chemicals during its resistance process and these chemicals can cause allergic reactions. One of them is 'histamine'. It will make the smallest blood vessels, i.e. capillaries, more permeable. Since more substances can penetrate capillaries, white blood cells can enter to resist allergic substances. But the problem is that the liquid also flows out more easily as well when white blood cells go in. So you may have runny nose, tears, etc. In addition, histamine can cause skin discomfort, such as itching and swelling. The symptoms of allergies vary in severity. In a severe case, it can even result in death. Therefore, if you have allergies, you should go to hospital in time and figure out your allergens."

"It turned out that sneezing and runny nose were caused by my own body. I thought pollens were to blame."

 “Actually, it is pollen's fault. Your immune system is also involved in the fight against pollens. So you can only say that both parties are 'wrong' in this process."

"Well, I won't play in the flowers anymore," Mackle curled his lips. He seemed to be reluctant to say that. But he must obey the rule for his own health. 

Author: Zhu Yawen